feat(flamegraph): added sub-second units support for trace visualization

packages/pyroscope-flamegraph/src/format/format.spec.ts

@@ -40,7 +40,6 @@ describe('format', () => {
       it('correctly formats trace samples', () => {
         const df = getFormatter(80, 2, 'trace_samples');
 
-        expect(df.format(0, 100)).toBe('0.00 seconds');
         expect(df.format(0.001, 100)).toBe('< 0.01 seconds');
         expect(df.format(100, 100)).toBe('1.00 second');
         expect(df.format(2000, 100)).toBe('20.00 seconds');
@@ -57,6 +56,72 @@ describe('format', () => {
         expect(df.format(2012.3, 100)).toBe('0.34 minutes');
         expect(df.format(8000, 100)).toBe('1.33 minutes');
       });
+
+      it('correctly formats trace_samples duration when maxdur is less than second', () => {
+        const df = getFormatter(10, 100, 'trace_samples');
+
+        expect(df.format(55, 100)).toBe('550.00 ms');
+        expect(df.format(100, 100)).toBe('1000.00 ms');
+        expect(df.format(1.001, 100)).toBe('10.01 ms');
+        expect(df.format(9999, 100)).toBe('99990.00 ms');
+        expect(df.format(0.331, 100)).toBe('3.31 ms');
+        expect(df.format(0.0001, 100)).toBe('< 0.01 ms');
+      });
+
+      it('correctly formats trace_samples duration when maxdur is less than ms', () => {
+        const df = getFormatter(1, 10000, 'trace_samples');
+
+        expect(df.format(0.012, 100)).toBe('120.00 μs');
+        expect(df.format(0, 100)).toBe('0.00 μs');
+        expect(df.format(0.0091, 100)).toBe('91.00 μs');
+        expect(df.format(1.005199, 100)).toBe('10051.99 μs');
+        expect(df.format(1.1, 100)).toBe('11000.00 μs');
+      });
+
+      it('correctly formats trace_samples duration when maxdur is hour', () => {
+        const hour = 3600;
+        let df = getFormatter(hour, 1, 'trace_samples');
+
+        expect(df.format(0, 100)).toBe('0.00 hours');
+        expect(df.format(hour * 100, 100)).toBe('1.00 hour');
+        expect(df.format(0.6 * hour * 100, 100)).toBe('0.60 hours');
+        expect(df.format(0.02 * hour * 100, 100)).toBe('0.02 hours');
+        expect(df.format(0.001 * hour * 100, 100)).toBe('< 0.01 hours');
+        expect(df.format(42.1 * hour * 100, 100)).toBe('42.10 hours');
+      });
+
+      it('correctly formats trace_samples duration when maxdur is day', () => {
+        const day = 24 * 60 * 60;
+        const df = getFormatter(day, 1, 'trace_samples');
+
+        expect(df.format(day * 100, 100)).toBe('1.00 day');
+        expect(df.format(12 * day * 100, 100)).toBe('12.00 days');
+        expect(df.format(2.29 * day * 100, 100)).toBe('2.29 days');
+        expect(df.format(0.11 * day * 100, 100)).toBe('0.11 days');
+        expect(df.format(0.001 * day * 100, 100)).toBe('< 0.01 days');
+      });
+
+      it('correctly formats trace_samples duration when maxdur = month', () => {
+        const month = 30 * 24 * 60 * 60;
+        const df = getFormatter(month, 1, 'trace_samples');
+
+        expect(df.format(month * 100, 100)).toBe('1.00 month');
+        expect(df.format(44 * month * 100, 100)).toBe('44.00 months');
+        expect(df.format(5.142 * month * 100, 100)).toBe('5.14 months');
+        expect(df.format(0.88 * month * 100, 100)).toBe('0.88 months');
+        expect(df.format(0.008 * month * 100, 100)).toBe('< 0.01 months');
+      });
+
+      it('correctly formats trace_samples duration when maxdur = year', () => {
+        const year = 12 * 30 * 24 * 60 * 60;
+        const df = getFormatter(year, 1, 'trace_samples');
+
+        expect(df.format(year * 100, 100)).toBe('1.00 year');
+        expect(df.format(12 * year * 100, 100)).toBe('12.00 years');
+        expect(df.format(3.414 * year * 100, 100)).toBe('3.41 years');
+        expect(df.format(0.12 * year * 100, 100)).toBe('0.12 years');
+        expect(df.format(0.008 * year * 100, 100)).toBe('< 0.01 years');
+      });
     });
 
     describe('ObjectsFormatter', () => {

packages/pyroscope-flamegraph/src/format/format.ts

@@ -29,7 +29,7 @@ export function getFormatter(max: number, sampleRate: number, unit: Units) {
     case 'lock_samples':
       return new ObjectsFormatter(max);
     case 'trace_samples':
-      return new DurationFormatter(max / sampleRate);
+      return new DurationFormatter(max / sampleRate, '', true);
     default:
       console.warn(`Unsupported unit: '${unit}'. Defaulting to ''`);
       return new DurationFormatter(max / sampleRate, ' ');
@@ -41,6 +41,8 @@ export function getFormatter(max: number, sampleRate: number, unit: Units) {
 class DurationFormatter {
   divider = 1;
 
+  enableSubsecondPrecision = false;
+
   suffix = 'second';
 
   durations: [number, string][] = [
@@ -53,7 +55,17 @@ class DurationFormatter {
 
   units = '';
 
-  constructor(maxDur: number, units?: string) {
+  constructor(
+    maxDur: number,
+    units?: string,
+    enableSubsecondPrecision?: boolean
+  ) {
+    if (enableSubsecondPrecision) {
+      this.enableSubsecondPrecision = enableSubsecondPrecision;
+      this.durations = [[1000, 'ms'], [1000, 'second'], ...this.durations];
+      this.suffix = `μs`;
+      maxDur *= 1e6; // Converting seconds to μs
+    }
     this.units = units || '';
     // eslint-disable-next-line no-plusplus
     for (let i = 0; i < this.durations.length; i++) {
@@ -74,7 +86,10 @@ class DurationFormatter {
     }
   }
 
-  format(samples: number, sampleRate: number) {
+  format(samples: number, sampleRate: number): string {
+    if (this.enableSubsecondPrecision) {
+      sampleRate /= 1e6;
+    }
     const n = samples / sampleRate / this.divider;
     let nStr = n.toFixed(2);
 
@@ -86,7 +101,10 @@ class DurationFormatter {
       nStr = '< 0.01';
     }
 
-    return `${nStr} ${this.units || `${this.suffix}${n === 1 ? '' : 's'}`}`;
+    return `${nStr} ${
+      this.units ||
+      `${this.suffix}${n === 1 || this.suffix.length === 2 ? '' : 's'}`
+    }`;
   }
 }